add hash method for Polys

Author: jverzani

src/Polynomials.jl

@@ -348,6 +348,8 @@ function ==(p1::Poly, p2::Poly)
     end
 end
 
+Base.hash(f::Poly, h::UInt) = hash(f.var, hash(f.a, h))
+
 """
 * `polyval(p::Poly, x::Number)`: Evaluate the polynomial `p` at `x` using Horner's method.
 

test/runtests.jl

@@ -246,3 +246,7 @@ r = Poly([1.0, 2, 3])
 @test string_eval_poly(q, 5) == q(5)
 @test string_eval_poly(r, 5) == r(5)
 
+## check hashing
+p = poly([1,2,3])
+q = poly([1,2,3])
+@test hash(p) == hash(q)